This invention relates to Q-switched lasers and more particularly to means for producing multiple laser pulses of different wavelengths from a single laser rod.
A variety of systems require the generation of two or more rapidly recurring laser pulses of substantially the same amplitude over a variable pulse interval wherein each of the pulses is of a different wave-length. U.S. Patent application Ser. No. 591,382 filed on June 23, 1975 for "Multiple Pulse Laser" discloses a laser for generating laser pulse doublets from a single laser rod at high efficiencies by temporally isolating the different light polarities from a single, thermally induced, stress-birefringent laser rod into two independent laser cavities which are independently Q-switched. However, this laser only produces pulses of the same wavelength.
In order to obtain multiple laser pulses of different wavelengths the system set forth in U.S. Patent application Ser. No. 559,295 filed on Mar. 17, 1975 for a "Multi-Color, Multi-Pulse Laser" was proposed. This laser system employs two cavities having a common optical leg each of which is tuned to a different transition of the laser medium such that when the laser emits at two different wavelengths each cavity will generate laser pulses at the respective wavelengths. This laser requires great care in the critical selection of a laser material which must generate substantial amounts of energy at different wavelengths.